Electrical junction boxes are typically used in automotive vehicles to streamline electrical wiring by eliminating multi-branch wiring. The junction box consolidates branch circuits, fuses, relays and other electrical circuit components into a single location. The junction box is usually located within a vehicle engine compartment and electrical connectors mounted on the box receive mating wiring harness connectors to connect the circuit components with various vehicle electrical devices, such as headlights, fuel pumps, windshield wiper motors and ignition switches.
The circuit components typically plug into cavities or receptacles in the junction box and have contacts in the form of blades or prongs that project through slots in the box to connect with bus bars or other conductive means housed within the box to join the components into electrical circuits. As the number and complexity of vehicle electrical systems has increased, the number of circuit components which must be mounted on a junction box has multiplied. Junction boxes are allotted a limited amount of space within an engine compartment, and once the available surface area of the box is fully utilized other locations for the necessary additional circuit components must be found.
One possible alternative to mounting circuit components on a junction block it to put them in line with a wire at some location remote from the block. U.S. Pat. No. 5,055,071 is an example of an in-line fuse holder for connecting a double-bladed fuse in series with an electrical wire. U.S. patent application Ser. No. 09/076,427, filed May 12, 1998, and assigned to the assignee of this application, discloses an electrical terminal having an integral positive temperature coefficient (PTC) device to protect associated circuitry against over-current conditions. Such a terminal eliminates the need for a separate circuit protection device associated with the particular wire to be located on a junction box, and may be incorporated into a multipin electrical connector. PTC overcurrent protection devices do not require replacement after an overcurrent condition has occurred. Rather, PTC devices are "self-resetting", so that once the overcurrent condition has ceased and the PTC device has cooled down to the normal operating temperature range, the device resumes normal operation and continues to provide protection for the circuit. The structure and operation of PTC devices are described in detail in U.S. Pat. No. 5,796,569, the disclosure of which is incorporated herein by reference.
FIGS. 1 and 2 show a prior art electrical connector 100 wherein terminals 102 attached to the ends of wires 113 are inserted into terminal chambers 104 within a connector housing 106 and held in place by flexible latch members 108 formed integrally with the connector housing. A rounded nub 110 on the surface of each latch member engages a shoulder 112 formed on the terminal 102 to prevent it from being pushed out of its chamber 104 by contact with a mating terminal, or pulled out of its chamber by tension on its attached wire 113. After the terminals 102 are inserted into their chambers 104, a locking wedge 114 is inserted into a receptacle 116 formed in the connector housing 106 adjacent the chambers 104 to wedge the latch members 108 into engagement with their respective terminals 102 and thereby positively lock them in place.